Big batteries soak up record amounts of energy as big solar floods the grid – but curtailment still bites

Battery storage in Australia's main grid hit a new record on Friday, holding 20.17 GWh of stored energy at 4:15 pm, triple the level recorded a year earlier. Utility-scale solar peaked at 10,561 MW the same day. Yet despite record battery deployment soaking up midday solar glut, curtailment remained severe: 41.36 GWh of generation was wasted across the day, including 26.67 GWh of solar. In New South Wales alone, 15.68 GWh of renewables was curtailed, mostly solar, even during periods when electricity prices were positive. The article notes that transmission constraints and local dispatch conditions, not just storage capacity, are driving the waste.

Where this fits

This is the reliability and cost pressure made visible. Tripling battery storage in a year is expensive. So is the overbuild of transmission needed to move solar and wind from where they're abundant to where they're needed. Curtailment, throwing away paid-for generation because the grid cannot absorb or move it, is the proof that firming capacity and wiring have fallen behind renewable build, not ahead of it. The whole-system cost of a weather-dependent grid includes the infrastructure you build and the generation you discard.

What it means

Australia is spending heavily on batteries and transmission to make solar work, yet still wastes tens of gigawatt-hours in a single day. This pattern will repeat and worsen as more solar and wind are added. A firm, non-weather-dependent source, nuclear is banned; gas fills the gap, would require no curtailment, no vast overbuild of storage and wires, and no strategic reliance on China's battery and inverter supply chains for the impossible task of firming weather.